Large-bore, lean-operating gas engines generally include a prechamber assembly in order to ensure ignition process in the engine. The prechamber assembly includes a prechamber volume, which is in fluid communication with a main combustion chamber of the engine via a number of small orifices. A spark plug associated with the prechamber assembly ignites a mixture of gaseous fuel and air present in the prechamber volume. Ignition of the mixture of gaseous fuel and air creates a front of burning fuel which is introduced in the main combustion chamber through the orifices. The prechamber assembly is subjected to high temperatures, especially where turbochargers are employed and engines are operating at high power density levels.
U.S. Pat. No. 8,757,127, hereinafter referred to as the '127 patent, describes a check valve structure capable of preventing soot accumulation in a check valve arranged in a prechamber assembly due to incomplete combustion of fuel gas and preventing malfunction of the check valve for a gas engine having a prechamber assembly with a spark plug. An arrangement for supplying fuel gas to the prechamber volume has multiple bore-cooling holes disposed around the spark plug for cooling a gasket formed in a mounting hardware piece, the holes having a lateral bore-cooling hole, and a lateral bore-cooling hole with the gasket therebetween. Each of the holes further has multiple bore-cooling holes parallel to the center axis of the spark plug. However, U.S. Pat. No. 8,757,127 does not describe a design that allows cooling of various portions of the prechamber assembly that are subjected to high temperatures during engine operation.